Caster



.-(Model.)

' M. B. SGHENCK.

GASTER.

No. 250,290. y Patented Nov. 29,1881.

f/TLFI; 2

y UNITED STATES g ATENT einen..

MARTIN B. SCHENGK, OF FULTON, NEW YORK.

CASTER.

SPECIFICATION forming part of Letters Patent No. 250,290, dated November 29, 1881.

' Application ined oct-ober 22,1881. (Model.)

To all whom it may concern:

Be it known that I, MARTIN B. SGHENCK, a citizen ofthe United States, residing at Fulton, in the county of Oswego and State of New York, have invented an Improvement in Casti ers, of which the following is a specication.

The subject ot this invention is a caster with two Hoor-wheels, the bearing-frame or housing of which is provided with an anti-friction roller, preferably located directly over the axis of the oor-wheels, running on the under surface ot' a track-plate, by which the caster may be secured to a'truck orto theleg ofany article of furniture. In the center of the attaching track-plate is a hemispherical bowl or concavity, forming a projecting boss on the under side, in the eenter of which is a cylindrical opening for the reception of a rigid stud projecting upward from the wheel-frame, said rigid stud constituting the vertical pintle on which the caster turns and the connection by which draft is applied from the attuchingplnte to the swiveledwheel-fratne. Thewheel-frameisattaehed to the traclrplate by means of a pin passed downward through the hollow stud and there secured, said pin having a head convex on 'the under side; or it maybe a hemispherical head, so as to form, in connection with the y bowl of the track-plate in which it rests, a universal or ball-and-socket joint, the aperture in the bottom of the bowl being of suicient size to afford free play in all directions.

In order that the invention may be fully understood, I will proceed to describe it with reference to the accompanying drawings, in which- Figure l is a front view ot' my improved caster. Fig. 2 is a side view. Fig. 3 is a vertical section on the line 3 3, Fig. 1. Fig. 4 is a similar section, illustrating a modicatio'n. Fig. 5 is an under-side view of the attaching or track plate.

A represents a track-plate, to be secured to the bottom of a truck or to the leg of any article of furniture to which the caster is to be applied. In the center of this plate is a downwardly-projecting bowl, B, of approximately spherical form, with an aperture, b, in its bottom.

C represents the housing or wheel-frame of the caster. It is constructed with suitable lugs, c c c, between which the two tioorwheels E E are confined, the said wheels running upon a horizontal pintle, F, extending through their hubs and through apertures prepared for them in the lower ends of the lugs c. The upper part of the housing or wheel-frame C is constructed with a hollow stud, D, extending upward within the aperture b of the bowl B, and forming the vertical pivot of the caster- 'rame and the means by which it is drawn when the truck or furniture to which it is attached is moved. The wheel-frame or housing G is attached or secured to the track-plate A by a pin, G, fixed by rivetingvor otherwise in the aperture ofthe hollow stud D, and having a head, g, resting in the depression B, and made convex on the under side, so as to afford the necessary lateral rocking motion to the frame.

The anti-friction wheel His located over, or nearly over, the horizontal axle or pintle F of the floor-wheels E. It turns on a bolt or pin, I, and bears upward against the under surface of the track-plate A.

The 'trackplate may be made round, as represented infull lines in Fig. 5, the form of the pivoted frame affording convenient access to screw-holes located at a a, within the track of the wheel H. This circular form of the plate avoids any projections which might obstruct the rotation ot' the frame; but, if preferred, the plate may have projecting lugs for the reeeption of screw-holes, as illustrated in dotted lines.

The rigid stud, which projects upward from the housing to form the vertical axis thereof and receive the draft, may be formed in one piece with the pin which holds the parts to gether, as illustrated in Fig. 4, where G represents the said attaching-pin and draft-stud g, its convex head rocking in the bowl B, as before, and d an enlargement or extended cylindrical collar, formed on the said pin or stud, to occupy the aperture b of the bowl B, the lower end of which collar or enlargement constitutesa shoulder, against which the Lipper face ot' the housing C is driven and secured in the act of riveting the lower end ot' the stud G permanently within it. It will be observed that by thus permanently fixing the stud or IOO ther secured by thev shoulder or enlargement d, forming afsolid bearing between `the stud and the housing, and being provided with a lip, d', to engage in a notch in the plate to prevent turning. Under this modification, as in the form of the invention first described, it will be observed that the draft is applied to the upper part of the caster-frame through the projecting upper part of the rigid stud.

In order to prevent the outer part of the caster-frame dropping when the truck or fur' niture is lifted from the door, the said frame is provided with a rearwardly-projecting rigid tail-piece, J, so nearly in contact with Ithe track-plate A that it will rest against it the moment the anti-friction wheel H drops therefrom.

I pref'er to place the anti-friction wheel -H directly over the Hoor-wheel axis,so that the caster will be balanced without any mateiial upward or downward strain while in use. By thuis balancing and centering the caster lavoid the binding and friction on the center `pintle which are caused by placing the anti-friction wheel on either side ofthe floor-wheel axis,as is the case with some double door-wheel casters heretofore devised and used.

It will be observed that my improved caster avoids the projection of any vertical stud or pintle below the caster-frame, and that the draft is applied directly to the upper part of the'caster-frarne instead of, as in some other casters, to the lower part of a vertical stud or bearing, which thus acts disadvantageously as a long lever, rendering it extremely liable to break the track-plate or draw out the screws bywhichit-is attached. The entire depth from the top of the attaching-plate to the bottom of the central part of the caster-frameis materially reduced by my improvement and the entire device rendered more compact.

These improvements are of great practical importance in the working of the caster, enhancing both its strength and durability, and also iii the appearance of the caster, rendering it much more neat and sightly.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

The combinationof the attaching track-plate A, formed with a centering-aperture, b, the housing C, having an upwardly-projecting rigid stud engaging in the aperture b and a connecting-rivet, the-two floor-wheels E, and theantifriction wheel El, all substantially'as set forth.

MARTIN B. 'SCHENCK.

Witnesses:

J. J. WRIGHT, 0. SEELY. 

